What is the primary function of observational studies?

The primary function of observational studies is to analyze subjects without any intervention. In observational studies, researchers observe and analyze the behaviors, characteristics, or outcomes of subjects in their natural settings. This approach allows for the collection of data regarding how variables of interest interact with each other in real-world contexts without altering any conditions or introducing any external manipulation.

By not intervening or manipulating the environment, researchers can gather insights about associations and trends that exist naturally among the subjects. This approach is particularly useful in situations where experiments would be unethical or impractical, such as studying disease prevalence, health behaviors, or social phenomena.

The other options refer to different methods of research. Testing hypotheses through controlled experiments is a characteristic of experimental studies, which seek to determine cause-and-effect relationships. Summarizing and describing statistical data is a function of descriptive statistics but does not encompass the broader aim of observational studies. Conducting interviews and surveys represents a methodology that can be used within various types of studies, including observational ones, but does not encapsulate the primary purpose of this research design. Thus, analyzing subjects without any intervention directly aligns with the essence of observational studies.